Data transmission, in particular of Internet data, using the ADSL standard, for example, is becoming increasingly more important inter alia in the private sector. As constantly increasing amounts of data have to be transmitted, the ADSL standard also has to be constantly developed and thus there are, for example, the transmission modes ADSL, ADSL+, ADSL2, ADSL2+ (including ADSL long reach), ADSL++ and ADSL2++ as well as a diagnostic mode called DrDSL. The ADSL types or ADSL flavours can be operated using single inverse fast Fourier transformation (1xIFFT) and apart from ADSL++ ADSL2++ also with double inverse fast Fourier transformation (2xIFFT).
In order to process ADSL data, interpolation or decimation of the data is required. A useful signal singly or doubly oversampled (1xIFFT/2xIFFT) by a data pump can be processed in an interpolation path. A received signal singly/doubly oversampled accordingly can be provided to a data pump in a decimation path. A higher data rate is achieved in each case due to the oversampling.
It is now desirable to provide circuits which can process a large number of ADSL transmission modes. One possibility for this purpose is to provide a separate interpolation path or decimation path for each ADSL transmission mode, a changeover being made between the paths, depending on the transmission standard currently being used. However, a solution of this type requires a large chip area and is therefore expensive to produce and it also has a relatively high power dissipation.
An object of the present invention is therefore to provide a method and a device for interpolating or decimating a signal, wherein a small chip area is required to implement the method and device and a power dissipation is reduced.